/*
 *    MeasureStreamSpeed.java
 *    Copyright (C) 2007 University of Waikato, Hamilton, New Zealand
 *    @author Richard Kirkby (rkirkby@cs.waikato.ac.nz)
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
package moa.tasks;

import moa.core.Measurement;
import moa.core.ObjectRepository;
import moa.core.TimingUtils;
import moa.evaluation.LearningEvaluation;
import moa.options.ClassOption;
import moa.options.IntOption;
import moa.streams.InstanceStream;

public class MeasureStreamSpeed extends MainTask {

	@Override
	public String getPurposeString() {
		return "Measures the speed of a stream.";
	}
	
	private static final long serialVersionUID = 1L;

	public ClassOption streamOption = new ClassOption("stream", 's',
			"Stream to measure.", InstanceStream.class,
			"generators.RandomTreeGenerator");

	public IntOption generateSizeOption = new IntOption("generateSize", 'g',
			"Number of examples.", 10000000, 0, Integer.MAX_VALUE);

	@Override
	protected Object doMainTask(TaskMonitor monitor, ObjectRepository repository) {
		TimingUtils.enablePreciseTiming();
		int numInstances = 0;
		InstanceStream stream = (InstanceStream) getPreparedClassOption(this.streamOption);
		long genStartTime = TimingUtils.getNanoCPUTimeOfCurrentThread();
		while (numInstances < this.generateSizeOption.getValue()) {
			stream.nextInstance();
			numInstances++;
		}
		double genTime = TimingUtils.nanoTimeToSeconds(TimingUtils
				.getNanoCPUTimeOfCurrentThread()
				- genStartTime);
		return new LearningEvaluation(
				new Measurement[] {
						new Measurement("Number of instances generated",
								numInstances),
						new Measurement("Time elapsed", genTime),
						new Measurement("Instances per second", numInstances
								/ genTime) });
	}

	public Class<?> getTaskResultType() {
		return LearningEvaluation.class;
	}

}
